65217216649 has 8 divisors (see below), whose sum is σ = 72132140360. Its totient is φ = 58573466496.

The previous prime is 65217216607. The next prime is 65217216677. The reversal of 65217216649 is 94661271256.

It can be written as a sum of positive squares in 4 ways, for example, as 609744249 + 64607472400 = 24693^2 + 254180^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 65217216649 - 2⁹ = 65217216137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65217211649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67792884 + ... + 67793845.

It is an arithmetic number, because the mean of its divisors is an integer number (9016517545).

Almost surely, 2^65217216649 is an apocalyptic number.

It is an amenable number.

65217216649 is a deficient number, since it is larger than the sum of its proper divisors (6914923711).

65217216649 is a wasteful number, since it uses less digits than its factorization.

65217216649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135586779.

The product of its digits is 1088640, while the sum is 49.

The spelling of 65217216649 in words is "sixty-five billion, two hundred seventeen million, two hundred sixteen thousand, six hundred forty-nine".